The Elden Ring Shadow of the Erdtree expansion boasts a multitude of unique and powerful weapons. One of the legendary blades is the Euporia Twinblade, which can be found in the later stages of the expansion. Here's what you need to do to get to this weapon.
This special weapon has a unique effect and is hidden on a secret path in the final Legacy Dungeon, Enir-Ilim.
Note. To reach this dungeon, you need to defeat Messmer the Impaler in the Shadow Keep and Romina, Saint of the Bud, in the western Ancient Ruins of Rauh. Using Messmer's Kindling on the sealing tree behind Romina's boss room will grant access to Enir-Ilim.
Although Euporia is technically located in Belurat, the Tower Settlement, its location is only accessible from above, in Enir-Ilim.
At the large staircase leading to the Spiral Rise to the Site of Grace, stop where you kill the first enemy constantly chanting spells, and find the ledge below you (or find the ladder on the side).
From the broken ledge, look further down, and you will see another large staircase, but you will have to make a huge jump to reach it. Climb the stairs and go through the round room to look out over the broken balcony.
Look carefully below, and you will be able to spot several arches protruding from the building and some corpses with shiny items that will help you. Jump to the wall to land safely on the ledge and walk along the arches to the south.
Once you reach the end of the arches, carefully round the corner to find the nearest tower to the south, wait for the protruding gargoyles, and jump down to land on the lower ledge. From here, you can look southeast and see a broken staircase leading to a large courtyard with a statue — here you will find the Scadutree Fragment, which you should definitely pick up along the way. Jump onto the staircase and go to the platform where the road forks.
From here, the only way forward is to make a deadly jump south into the window (you must not bounce off), then jump down and re-enter Belurat.
Exit the altar room and look left to see a large statue draped in cloth, and at the base of this statue is the Scadutree Fragment (be careful, a large spider-scorpion might ambush you!).
You need to continue south to the large elevator that will take you to the area above the main part of Belurat. You can even look down from the balcony and see the Divine Beast Dancing Lion's theatre to the left.
Keep descending the new staircase through a small room full of inquisitors and head southwest to the final dangerous opponent — the Divine Beast Warrior. Beware of its lightning attacks and defeat it with cautious strikes.
Past the warrior, you can enter a room with a spiral staircase leading down to an elevator. This will take you to a bridge over the large poisonous moat of Belurat, which you previously could not access. Cross the bridge and open the large door, and you will discover a huge altar room where Euporia awaits.
Euporia is different from other weapons in that its blades are initially dimmed, but by attacking enemies, you can gradually enhance the weapon and make it glow. When you reach several levels of enhancement, an audible signal will sound, and its weapon skill, Euporia Vortex, will allow you to release the accumulated energy.
Using the special move on its own will allow you to quickly spin the twinblade in front of you, dealing damage to anyone in front of you. However, when the twinblade is glowing and charged, using the ability will add light beams! The more charge you have accumulated, the longer the beams will attack the enemies you are facing.
Note that due to its properties, the blade cannot be charged by attacking those who are already dead, including enemies like skeletons.